Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 771 insertions, 0 deletions

diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
new file mode 100644
index 000000000000..59e7c6317872
--- /dev/null
+++ b/net/ipv6/reassembly.c
@@ -0,0 +1,771 @@
+/*
+ *	IPv6 fragment reassembly
+ *	Linux INET6 implementation 
+ *
+ *	Authors:
+ *	Pedro Roque		<roque@di.fc.ul.pt>	
+ *
+ *	$Id: reassembly.c,v 1.26 2001/03/07 22:00:57 davem Exp $
+ *
+ *	Based on: net/ipv4/ip_fragment.c
+ *
+ *	This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+/* 
+ *	Fixes:	
+ *	Andi Kleen	Make it work with multiple hosts.
+ *			More RFC compliance.
+ *
+ *      Horst von Brand Add missing #include <linux/string.h>
+ *	Alexey Kuznetsov	SMP races, threading, cleanup.
+ *	Patrick McHardy		LRU queue of frag heads for evictor.
+ *	Mitsuru KANDA @USAGI	Register inet6_protocol{}.
+ *	David Stevens and
+ *	YOSHIFUJI,H. @USAGI	Always remove fragment header to
+ *				calculate ICV correctly.
+ */
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/jiffies.h>
+#include <linux/net.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/in6.h>
+#include <linux/ipv6.h>
+#include <linux/icmpv6.h>
+#include <linux/random.h>
+#include <linux/jhash.h>
+
+#include <net/sock.h>
+#include <net/snmp.h>
+
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <net/transp_v6.h>
+#include <net/rawv6.h>
+#include <net/ndisc.h>
+#include <net/addrconf.h>
+
+int sysctl_ip6frag_high_thresh = 256*1024;
+int sysctl_ip6frag_low_thresh = 192*1024;
+
+int sysctl_ip6frag_time = IPV6_FRAG_TIMEOUT;
+
+struct ip6frag_skb_cb
+{
+	struct inet6_skb_parm	h;
+	int			offset;
+};
+
+#define FRAG6_CB(skb)	((struct ip6frag_skb_cb*)((skb)->cb))
+
+
+/*
+ *	Equivalent of ipv4 struct ipq
+ */
+
+struct frag_queue
+{
+	struct frag_queue	*next;
+	struct list_head lru_list;		/* lru list member	*/
+
+	__u32			id;		/* fragment id		*/
+	struct in6_addr		saddr;
+	struct in6_addr		daddr;
+
+	spinlock_t		lock;
+	atomic_t		refcnt;
+	struct timer_list	timer;		/* expire timer		*/
+	struct sk_buff		*fragments;
+	int			len;
+	int			meat;
+	int			iif;
+	struct timeval		stamp;
+	unsigned int		csum;
+	__u8			last_in;	/* has first/last segment arrived? */
+#define COMPLETE		4
+#define FIRST_IN		2
+#define LAST_IN			1
+	__u16			nhoffset;
+	struct frag_queue	**pprev;
+};
+
+/* Hash table. */
+
+#define IP6Q_HASHSZ	64
+
+static struct frag_queue *ip6_frag_hash[IP6Q_HASHSZ];
+static DEFINE_RWLOCK(ip6_frag_lock);
+static u32 ip6_frag_hash_rnd;
+static LIST_HEAD(ip6_frag_lru_list);
+int ip6_frag_nqueues = 0;
+
+static __inline__ void __fq_unlink(struct frag_queue *fq)
+{
+	if(fq->next)
+		fq->next->pprev = fq->pprev;
+	*fq->pprev = fq->next;
+	list_del(&fq->lru_list);
+	ip6_frag_nqueues--;
+}
+
+static __inline__ void fq_unlink(struct frag_queue *fq)
+{
+	write_lock(&ip6_frag_lock);
+	__fq_unlink(fq);
+	write_unlock(&ip6_frag_lock);
+}
+
+static unsigned int ip6qhashfn(u32 id, struct in6_addr *saddr,
+			       struct in6_addr *daddr)
+{
+	u32 a, b, c;
+
+	a = saddr->s6_addr32[0];
+	b = saddr->s6_addr32[1];
+	c = saddr->s6_addr32[2];
+
+	a += JHASH_GOLDEN_RATIO;
+	b += JHASH_GOLDEN_RATIO;
+	c += ip6_frag_hash_rnd;
+	__jhash_mix(a, b, c);
+
+	a += saddr->s6_addr32[3];
+	b += daddr->s6_addr32[0];
+	c += daddr->s6_addr32[1];
+	__jhash_mix(a, b, c);
+
+	a += daddr->s6_addr32[2];
+	b += daddr->s6_addr32[3];
+	c += id;
+	__jhash_mix(a, b, c);
+
+	return c & (IP6Q_HASHSZ - 1);
+}
+
+static struct timer_list ip6_frag_secret_timer;
+int sysctl_ip6frag_secret_interval = 10 * 60 * HZ;
+
+static void ip6_frag_secret_rebuild(unsigned long dummy)
+{
+	unsigned long now = jiffies;
+	int i;
+
+	write_lock(&ip6_frag_lock);
+	get_random_bytes(&ip6_frag_hash_rnd, sizeof(u32));
+	for (i = 0; i < IP6Q_HASHSZ; i++) {
+		struct frag_queue *q;
+
+		q = ip6_frag_hash[i];
+		while (q) {
+			struct frag_queue *next = q->next;
+			unsigned int hval = ip6qhashfn(q->id,
+						       &q->saddr,
+						       &q->daddr);
+
+			if (hval != i) {
+				/* Unlink. */
+				if (q->next)
+					q->next->pprev = q->pprev;
+				*q->pprev = q->next;
+
+				/* Relink to new hash chain. */
+				if ((q->next = ip6_frag_hash[hval]) != NULL)
+					q->next->pprev = &q->next;
+				ip6_frag_hash[hval] = q;
+				q->pprev = &ip6_frag_hash[hval];
+			}
+
+			q = next;
+		}
+	}
+	write_unlock(&ip6_frag_lock);
+
+	mod_timer(&ip6_frag_secret_timer, now + sysctl_ip6frag_secret_interval);
+}
+
+atomic_t ip6_frag_mem = ATOMIC_INIT(0);
+
+/* Memory Tracking Functions. */
+static inline void frag_kfree_skb(struct sk_buff *skb, int *work)
+{
+	if (work)
+		*work -= skb->truesize;
+	atomic_sub(skb->truesize, &ip6_frag_mem);
+	kfree_skb(skb);
+}
+
+static inline void frag_free_queue(struct frag_queue *fq, int *work)
+{
+	if (work)
+		*work -= sizeof(struct frag_queue);
+	atomic_sub(sizeof(struct frag_queue), &ip6_frag_mem);
+	kfree(fq);
+}
+
+static inline struct frag_queue *frag_alloc_queue(void)
+{
+	struct frag_queue *fq = kmalloc(sizeof(struct frag_queue), GFP_ATOMIC);
+
+	if(!fq)
+		return NULL;
+	atomic_add(sizeof(struct frag_queue), &ip6_frag_mem);
+	return fq;
+}
+
+/* Destruction primitives. */
+
+/* Complete destruction of fq. */
+static void ip6_frag_destroy(struct frag_queue *fq, int *work)
+{
+	struct sk_buff *fp;
+
+	BUG_TRAP(fq->last_in&COMPLETE);
+	BUG_TRAP(del_timer(&fq->timer) == 0);
+
+	/* Release all fragment data. */
+	fp = fq->fragments;
+	while (fp) {
+		struct sk_buff *xp = fp->next;
+
+		frag_kfree_skb(fp, work);
+		fp = xp;
+	}
+
+	frag_free_queue(fq, work);
+}
+
+static __inline__ void fq_put(struct frag_queue *fq, int *work)
+{
+	if (atomic_dec_and_test(&fq->refcnt))
+		ip6_frag_destroy(fq, work);
+}
+
+/* Kill fq entry. It is not destroyed immediately,
+ * because caller (and someone more) holds reference count.
+ */
+static __inline__ void fq_kill(struct frag_queue *fq)
+{
+	if (del_timer(&fq->timer))
+		atomic_dec(&fq->refcnt);
+
+	if (!(fq->last_in & COMPLETE)) {
+		fq_unlink(fq);
+		atomic_dec(&fq->refcnt);
+		fq->last_in |= COMPLETE;
+	}
+}
+
+static void ip6_evictor(void)
+{
+	struct frag_queue *fq;
+	struct list_head *tmp;
+	int work;
+
+	work = atomic_read(&ip6_frag_mem) - sysctl_ip6frag_low_thresh;
+	if (work <= 0)
+		return;
+
+	while(work > 0) {
+		read_lock(&ip6_frag_lock);
+		if (list_empty(&ip6_frag_lru_list)) {
+			read_unlock(&ip6_frag_lock);
+			return;
+		}
+		tmp = ip6_frag_lru_list.next;
+		fq = list_entry(tmp, struct frag_queue, lru_list);
+		atomic_inc(&fq->refcnt);
+		read_unlock(&ip6_frag_lock);
+
+		spin_lock(&fq->lock);
+		if (!(fq->last_in&COMPLETE))
+			fq_kill(fq);
+		spin_unlock(&fq->lock);
+
+		fq_put(fq, &work);
+		IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+	}
+}
+
+static void ip6_frag_expire(unsigned long data)
+{
+	struct frag_queue *fq = (struct frag_queue *) data;
+
+	spin_lock(&fq->lock);
+
+	if (fq->last_in & COMPLETE)
+		goto out;
+
+	fq_kill(fq);
+
+	IP6_INC_STATS_BH(IPSTATS_MIB_REASMTIMEOUT);
+	IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+
+	/* Send error only if the first segment arrived. */
+	if (fq->last_in&FIRST_IN && fq->fragments) {
+		struct net_device *dev = dev_get_by_index(fq->iif);
+
+		/*
+		   But use as source device on which LAST ARRIVED
+		   segment was received. And do not use fq->dev
+		   pointer directly, device might already disappeared.
+		 */
+		if (dev) {
+			fq->fragments->dev = dev;
+			icmpv6_send(fq->fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0,
+				    dev);
+			dev_put(dev);
+		}
+	}
+out:
+	spin_unlock(&fq->lock);
+	fq_put(fq, NULL);
+}
+
+/* Creation primitives. */
+
+
+static struct frag_queue *ip6_frag_intern(unsigned int hash,
+					  struct frag_queue *fq_in)
+{
+	struct frag_queue *fq;
+
+	write_lock(&ip6_frag_lock);
+#ifdef CONFIG_SMP
+	for (fq = ip6_frag_hash[hash]; fq; fq = fq->next) {
+		if (fq->id == fq_in->id && 
+		    ipv6_addr_equal(&fq_in->saddr, &fq->saddr) &&
+		    ipv6_addr_equal(&fq_in->daddr, &fq->daddr)) {
+			atomic_inc(&fq->refcnt);
+			write_unlock(&ip6_frag_lock);
+			fq_in->last_in |= COMPLETE;
+			fq_put(fq_in, NULL);
+			return fq;
+		}
+	}
+#endif
+	fq = fq_in;
+
+	if (!mod_timer(&fq->timer, jiffies + sysctl_ip6frag_time))
+		atomic_inc(&fq->refcnt);
+
+	atomic_inc(&fq->refcnt);
+	if((fq->next = ip6_frag_hash[hash]) != NULL)
+		fq->next->pprev = &fq->next;
+	ip6_frag_hash[hash] = fq;
+	fq->pprev = &ip6_frag_hash[hash];
+	INIT_LIST_HEAD(&fq->lru_list);
+	list_add_tail(&fq->lru_list, &ip6_frag_lru_list);
+	ip6_frag_nqueues++;
+	write_unlock(&ip6_frag_lock);
+	return fq;
+}
+
+
+static struct frag_queue *
+ip6_frag_create(unsigned int hash, u32 id, struct in6_addr *src, struct in6_addr *dst)
+{
+	struct frag_queue *fq;
+
+	if ((fq = frag_alloc_queue()) == NULL)
+		goto oom;
+
+	memset(fq, 0, sizeof(struct frag_queue));
+
+	fq->id = id;
+	ipv6_addr_copy(&fq->saddr, src);
+	ipv6_addr_copy(&fq->daddr, dst);
+
+	init_timer(&fq->timer);
+	fq->timer.function = ip6_frag_expire;
+	fq->timer.data = (long) fq;
+	spin_lock_init(&fq->lock);
+	atomic_set(&fq->refcnt, 1);
+
+	return ip6_frag_intern(hash, fq);
+
+oom:
+	IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+	return NULL;
+}
+
+static __inline__ struct frag_queue *
+fq_find(u32 id, struct in6_addr *src, struct in6_addr *dst)
+{
+	struct frag_queue *fq;
+	unsigned int hash = ip6qhashfn(id, src, dst);
+
+	read_lock(&ip6_frag_lock);
+	for(fq = ip6_frag_hash[hash]; fq; fq = fq->next) {
+		if (fq->id == id && 
+		    ipv6_addr_equal(src, &fq->saddr) &&
+		    ipv6_addr_equal(dst, &fq->daddr)) {
+			atomic_inc(&fq->refcnt);
+			read_unlock(&ip6_frag_lock);
+			return fq;
+		}
+	}
+	read_unlock(&ip6_frag_lock);
+
+	return ip6_frag_create(hash, id, src, dst);
+}
+
+
+static void ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, 
+			   struct frag_hdr *fhdr, int nhoff)
+{
+	struct sk_buff *prev, *next;
+	int offset, end;
+
+	if (fq->last_in & COMPLETE)
+		goto err;
+
+	offset = ntohs(fhdr->frag_off) & ~0x7;
+	end = offset + (ntohs(skb->nh.ipv6h->payload_len) -
+			((u8 *) (fhdr + 1) - (u8 *) (skb->nh.ipv6h + 1)));
+
+	if ((unsigned int)end > IPV6_MAXPLEN) {
+		IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+ 		icmpv6_param_prob(skb,ICMPV6_HDR_FIELD, (u8*)&fhdr->frag_off - skb->nh.raw);
+ 		return;
+	}
+
+ 	if (skb->ip_summed == CHECKSUM_HW)
+ 		skb->csum = csum_sub(skb->csum,
+ 				     csum_partial(skb->nh.raw, (u8*)(fhdr+1)-skb->nh.raw, 0));
+
+	/* Is this the final fragment? */
+	if (!(fhdr->frag_off & htons(IP6_MF))) {
+		/* If we already have some bits beyond end
+		 * or have different end, the segment is corrupted.
+		 */
+		if (end < fq->len ||
+		    ((fq->last_in & LAST_IN) && end != fq->len))
+			goto err;
+		fq->last_in |= LAST_IN;
+		fq->len = end;
+	} else {
+		/* Check if the fragment is rounded to 8 bytes.
+		 * Required by the RFC.
+		 */
+		if (end & 0x7) {
+			/* RFC2460 says always send parameter problem in
+			 * this case. -DaveM
+			 */
+			IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+			icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 
+					  offsetof(struct ipv6hdr, payload_len));
+			return;
+		}
+		if (end > fq->len) {
+			/* Some bits beyond end -> corruption. */
+			if (fq->last_in & LAST_IN)
+				goto err;
+			fq->len = end;
+		}
+	}
+
+	if (end == offset)
+		goto err;
+
+	/* Point into the IP datagram 'data' part. */
+	if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
+		goto err;
+	if (end-offset < skb->len) {
+		if (pskb_trim(skb, end - offset))
+			goto err;
+		if (skb->ip_summed != CHECKSUM_UNNECESSARY)
+			skb->ip_summed = CHECKSUM_NONE;
+	}
+
+	/* Find out which fragments are in front and at the back of us
+	 * in the chain of fragments so far.  We must know where to put
+	 * this fragment, right?
+	 */
+	prev = NULL;
+	for(next = fq->fragments; next != NULL; next = next->next) {
+		if (FRAG6_CB(next)->offset >= offset)
+			break;	/* bingo! */
+		prev = next;
+	}
+
+	/* We found where to put this one.  Check for overlap with
+	 * preceding fragment, and, if needed, align things so that
+	 * any overlaps are eliminated.
+	 */
+	if (prev) {
+		int i = (FRAG6_CB(prev)->offset + prev->len) - offset;
+
+		if (i > 0) {
+			offset += i;
+			if (end <= offset)
+				goto err;
+			if (!pskb_pull(skb, i))
+				goto err;
+			if (skb->ip_summed != CHECKSUM_UNNECESSARY)
+				skb->ip_summed = CHECKSUM_NONE;
+		}
+	}
+
+	/* Look for overlap with succeeding segments.
+	 * If we can merge fragments, do it.
+	 */
+	while (next && FRAG6_CB(next)->offset < end) {
+		int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */
+
+		if (i < next->len) {
+			/* Eat head of the next overlapped fragment
+			 * and leave the loop. The next ones cannot overlap.
+			 */
+			if (!pskb_pull(next, i))
+				goto err;
+			FRAG6_CB(next)->offset += i;	/* next fragment */
+			fq->meat -= i;
+			if (next->ip_summed != CHECKSUM_UNNECESSARY)
+				next->ip_summed = CHECKSUM_NONE;
+			break;
+		} else {
+			struct sk_buff *free_it = next;
+
+			/* Old fragment is completely overridden with
+			 * new one drop it.
+			 */
+			next = next->next;
+
+			if (prev)
+				prev->next = next;
+			else
+				fq->fragments = next;
+
+			fq->meat -= free_it->len;
+			frag_kfree_skb(free_it, NULL);
+		}
+	}
+
+	FRAG6_CB(skb)->offset = offset;
+
+	/* Insert this fragment in the chain of fragments. */
+	skb->next = next;
+	if (prev)
+		prev->next = skb;
+	else
+		fq->fragments = skb;
+
+	if (skb->dev)
+		fq->iif = skb->dev->ifindex;
+	skb->dev = NULL;
+	fq->stamp = skb->stamp;
+	fq->meat += skb->len;
+	atomic_add(skb->truesize, &ip6_frag_mem);
+
+	/* The first fragment.
+	 * nhoffset is obtained from the first fragment, of course.
+	 */
+	if (offset == 0) {
+		fq->nhoffset = nhoff;
+		fq->last_in |= FIRST_IN;
+	}
+	write_lock(&ip6_frag_lock);
+	list_move_tail(&fq->lru_list, &ip6_frag_lru_list);
+	write_unlock(&ip6_frag_lock);
+	return;
+
+err:
+	IP6_INC_STATS(IPSTATS_MIB_REASMFAILS);
+	kfree_skb(skb);
+}
+
+/*
+ *	Check if this packet is complete.
+ *	Returns NULL on failure by any reason, and pointer
+ *	to current nexthdr field in reassembled frame.
+ *
+ *	It is called with locked fq, and caller must check that
+ *	queue is eligible for reassembly i.e. it is not COMPLETE,
+ *	the last and the first frames arrived and all the bits are here.
+ */
+static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff **skb_in,
+			  unsigned int *nhoffp,
+			  struct net_device *dev)
+{
+	struct sk_buff *fp, *head = fq->fragments;
+	int    payload_len;
+	unsigned int nhoff;
+
+	fq_kill(fq);
+
+	BUG_TRAP(head != NULL);
+	BUG_TRAP(FRAG6_CB(head)->offset == 0);
+
+	/* Unfragmented part is taken from the first segment. */
+	payload_len = (head->data - head->nh.raw) - sizeof(struct ipv6hdr) + fq->len - sizeof(struct frag_hdr);
+	if (payload_len > IPV6_MAXPLEN)
+		goto out_oversize;
+
+	/* Head of list must not be cloned. */
+	if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
+		goto out_oom;
+
+	/* If the first fragment is fragmented itself, we split
+	 * it to two chunks: the first with data and paged part
+	 * and the second, holding only fragments. */
+	if (skb_shinfo(head)->frag_list) {
+		struct sk_buff *clone;
+		int i, plen = 0;
+
+		if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
+			goto out_oom;
+		clone->next = head->next;
+		head->next = clone;
+		skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
+		skb_shinfo(head)->frag_list = NULL;
+		for (i=0; i<skb_shinfo(head)->nr_frags; i++)
+			plen += skb_shinfo(head)->frags[i].size;
+		clone->len = clone->data_len = head->data_len - plen;
+		head->data_len -= clone->len;
+		head->len -= clone->len;
+		clone->csum = 0;
+		clone->ip_summed = head->ip_summed;
+		atomic_add(clone->truesize, &ip6_frag_mem);
+	}
+
+	/* We have to remove fragment header from datagram and to relocate
+	 * header in order to calculate ICV correctly. */
+	nhoff = fq->nhoffset;
+	head->nh.raw[nhoff] = head->h.raw[0];
+	memmove(head->head + sizeof(struct frag_hdr), head->head, 
+		(head->data - head->head) - sizeof(struct frag_hdr));
+	head->mac.raw += sizeof(struct frag_hdr);
+	head->nh.raw += sizeof(struct frag_hdr);
+
+	skb_shinfo(head)->frag_list = head->next;
+	head->h.raw = head->data;
+	skb_push(head, head->data - head->nh.raw);
+	atomic_sub(head->truesize, &ip6_frag_mem);
+
+	for (fp=head->next; fp; fp = fp->next) {
+		head->data_len += fp->len;
+		head->len += fp->len;
+		if (head->ip_summed != fp->ip_summed)
+			head->ip_summed = CHECKSUM_NONE;
+		else if (head->ip_summed == CHECKSUM_HW)
+			head->csum = csum_add(head->csum, fp->csum);
+		head->truesize += fp->truesize;
+		atomic_sub(fp->truesize, &ip6_frag_mem);
+	}
+
+	head->next = NULL;
+	head->dev = dev;
+	head->stamp = fq->stamp;
+	head->nh.ipv6h->payload_len = htons(payload_len);
+
+	*skb_in = head;
+
+	/* Yes, and fold redundant checksum back. 8) */
+	if (head->ip_summed == CHECKSUM_HW)
+		head->csum = csum_partial(head->nh.raw, head->h.raw-head->nh.raw, head->csum);
+
+	IP6_INC_STATS_BH(IPSTATS_MIB_REASMOKS);
+	fq->fragments = NULL;
+	*nhoffp = nhoff;
+	return 1;
+
+out_oversize:
+	if (net_ratelimit())
+		printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
+	goto out_fail;
+out_oom:
+	if (net_ratelimit())
+		printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
+out_fail:
+	IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+	return -1;
+}
+
+static int ipv6_frag_rcv(struct sk_buff **skbp, unsigned int *nhoffp)
+{
+	struct sk_buff *skb = *skbp; 
+	struct net_device *dev = skb->dev;
+	struct frag_hdr *fhdr;
+	struct frag_queue *fq;
+	struct ipv6hdr *hdr;
+
+	hdr = skb->nh.ipv6h;
+
+	IP6_INC_STATS_BH(IPSTATS_MIB_REASMREQDS);
+
+	/* Jumbo payload inhibits frag. header */
+	if (hdr->payload_len==0) {
+		IP6_INC_STATS(IPSTATS_MIB_INHDRERRORS);
+		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb->h.raw-skb->nh.raw);
+		return -1;
+	}
+	if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+sizeof(struct frag_hdr))) {
+		IP6_INC_STATS(IPSTATS_MIB_INHDRERRORS);
+		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb->h.raw-skb->nh.raw);
+		return -1;
+	}
+
+	hdr = skb->nh.ipv6h;
+	fhdr = (struct frag_hdr *)skb->h.raw;
+
+	if (!(fhdr->frag_off & htons(0xFFF9))) {
+		/* It is not a fragmented frame */
+		skb->h.raw += sizeof(struct frag_hdr);
+		IP6_INC_STATS_BH(IPSTATS_MIB_REASMOKS);
+
+		*nhoffp = (u8*)fhdr - skb->nh.raw;
+		return 1;
+	}
+
+	if (atomic_read(&ip6_frag_mem) > sysctl_ip6frag_high_thresh)
+		ip6_evictor();
+
+	if ((fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr)) != NULL) {
+		int ret = -1;
+
+		spin_lock(&fq->lock);
+
+		ip6_frag_queue(fq, skb, fhdr, *nhoffp);
+
+		if (fq->last_in == (FIRST_IN|LAST_IN) &&
+		    fq->meat == fq->len)
+			ret = ip6_frag_reasm(fq, skbp, nhoffp, dev);
+
+		spin_unlock(&fq->lock);
+		fq_put(fq, NULL);
+		return ret;
+	}
+
+	IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+	kfree_skb(skb);
+	return -1;
+}
+
+static struct inet6_protocol frag_protocol =
+{
+	.handler	=	ipv6_frag_rcv,
+	.flags		=	INET6_PROTO_NOPOLICY,
+};
+
+void __init ipv6_frag_init(void)
+{
+	if (inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT) < 0)
+		printk(KERN_ERR "ipv6_frag_init: Could not register protocol\n");
+
+	ip6_frag_hash_rnd = (u32) ((num_physpages ^ (num_physpages>>7)) ^
+				   (jiffies ^ (jiffies >> 6)));
+
+	init_timer(&ip6_frag_secret_timer);
+	ip6_frag_secret_timer.function = ip6_frag_secret_rebuild;
+	ip6_frag_secret_timer.expires = jiffies + sysctl_ip6frag_secret_interval;
+	add_timer(&ip6_frag_secret_timer);
+}